Yes, it is : believe me : I'm using the be-latin1 keyboard layout myself The "strange" part in anaconda (which was completely rewritten "from scratch") is that they call it "Dutch; Flemish (Belgian)".If during install you just type "belgian" you'll also see it in the list.

The belgian keyboard has always been referred to as "Belgian French", which does make sense, since french-speaking belgian residents need the same accented letters on the keyboard as residents of France. Dutch-speaking belgians, in turn, could use a standard qwerty keyboard as well, they use accented letters in only rare occasions. As Anaconda has been re-written, I would assume that the only belgian participants are flemish, and that they have recently voted for some flemish nationalist party...